The use of security systems is generally well known. There use is becoming even greater with increased availability of digital electronic components at a relatively low cost. Such systems are known for securing buildings, banks, automobiles, computers and many other devices. For example, U.S. Pat. No. 4,951,249 discloses a computer security system which protects computer software from unauthorized access by requiring the user to supply a name and a password during the operating system loading procedure ("boot-up") of a personal computer (PC). This is accomplished by the insertion of a special card into an input/output expansion slot of the PC. During the loading of the operating system of the PC, the basic input/output system (BIOS) scans memory addresses of the card for an identification code, consisting of a 55AA hex code. When this hex code is located, the BIOS instructions are vectored to the address where the target hex code resides and instructions at the following address are executed as part of the initialization routines of the system boot-up procedure.
This PC security system, utilizing a password board, is typical of many systems that are currently available. Password boards require a user's name and a password associated with that user's name. Only once a password board detects a valid user's name and password does it allow the PC to complete the boot-up routine. Though password boards may be useful in some instances, they are inadequate in many respects.
For example, an unauthorized skilled user with a correct password in hand, can gain entry to such a processor based system. Yet another undesirable feature of the foregoing system is that passwords on occasion are forgotten; and furthermore, and more importantly, passwords have been known to be decrypted.
As of late one of the most ubiquitous electronic components is the digital processor. Multi-purpose and dedicated processors of various types control devices ranging from bank machines, to cash registers and automobiles. With ever increasing use of these processor based devices, there is greater concern that unauthorized use will become more prevalent. Thus, the verification and/or authentication of authorized users of processor based systems is a burgeoning industry.
Alarms and security systems to warn of unauthorized use of automobiles and other processor controlled systems are available, however, these security systems have been known to be circumvented. Furthermore, automobile alarms that sound, are often ignored by passers-by. Unfortunately, many commercially available solutions aimed at preventing theft or unauthorized use of automobiles have also been circumvented.
Thus, it is an object of this invention to provide a method and relatively inexpensive system for preventing unauthorized use of a vehicle controlled by a processor based control system.